one of my most used features is Apple Car Play. It's very annoying that you have to start the spotify app at your iOS device before you can play music. Is the app closed and you tap the Spotify icon in your car, you can not press the play button, so no music is played. After starting the app at the iOS device playback gets working. Apple Music is better in this point. I think it is a bug?
Furthermore it would be nice to enable shuffle playback even a playlist plays. At the moment you can switch between normal and shuffle playback only at the beginning, but not when tracks of your playlists are already playing. Second "request" is that it would be nice to have the playlist sorting even in carplay.